Material dispensing and applicating apparatus



Sept. 4, 1962 G. P. ADAMS ETAL 3,052,203

MATERIAL DISPENSING AND APPLICATING APPARATUS Filed June 9, 1960 4 Sheets-Sheet l A. 6. SOURCE INVENTORS G ADAMS l/ A. RAVBURN BY 0(9 07x AT TORNEV Sept. 4, 1962 G. P. ADAMS ETAL 3,052,208

MATERIAL DISPENSING AND APPLICATING APPARATUS 4 Sheets-Sheet 2 Filed June 9, 1960 iI-IEPIIIIIIIIIII 5 R N mS M M Y@ w. A Y 0 AN 7 w VA g M w 4 4 G. 6 a 6 Q 6 M w W :1 W7% W w m 0 I /T Sept. 4, 1962 G. P. ADAMS ETAL 3,052,208

MATERIAL DISPENSING AND APPLICATING APPARATUS Filed June 9, 1960 4 Sheets-Sheet 3 I r llfi /9 b II" I! 27 4| INVENTORS G. P ADAMS BY l/ A. RAYBURN 0 m a BM A T TORNEV Sept. 4, 1962 G. P. ADAMS ETAL 3,052,208

MATERIAL DISPENSING AND APPLICATING APPARATUS Filed June 9, 1960 4 Sheets-Sheet 4 INVENTORS G. P ADAMS BY 1! A. RA VBURN KQMQAM A T TORNE Y Unite States Patent 3,052,208 MATERIAL DISPENSHNG AND APPLICATING APPARATUS George I. Adams and Vincent A. Rayburn, Baltimore,

Md, assignors to Western Electric Company, Incorporated, a corporation of New York Filed June 9, 1960, Ser. No. 34,950 9 Claims. (Cl. 118-2) The present invention relates to a material dispensing and applicatin-g apparatus, and more particularly, although not exclusively, to a cement applicator having a pair of opposed, movable nozzles designed to apply parallel worms or threads of lead oxide-boric anhydride frit cement to porcelain blocks immediately adjacent to the sides of carbon inserts in the porcelain blocks of lightning protectors for communications equipment.

In an initial step of assemblage of a carbon insert in an aperture of a porcelain block during the manufacture of lightning protectors for communications equipment, it is customary to cement a generally rectangular carbon insert in a complementary rectangular aperture of a rectangular porcelain block. In the past, it has been customary to cement the carbon insert in the porcelain block by applying powdered frit in and around the region of the contiguous portions of the carbon insert and the porcelain block. The porcelain block and carbon insert in the aperture thereof, with the powdered frit thereon, were passed through a furnace to fuse the frit which, in turn, secures the carbon insert in the aperture of the porcelain block. However, more recently it has been found more desirable to apply the frit to the protector block immediately adjacent to the sides of the carbon inserts in paste form, instead of powdered form.

'It is an object of the present invention to provide a new and improved material dispensing and applicating apparatus.

Another object of the present invention is to provide a new and improved cement applicator.

A further object of the present invention is to provide a new and improved cement applicator having a pair of opposed, movable nozzles designed to apply parallel worms or threads of lead oxide-'boric anhydride frit cement to porcelain blocks immediately adjacent to the sides of carbon inserts in porcelain blocks of lightning protectors for communications equipment.

A material dispensing and applicating apparatus embodying certain principles of the present invention may include means for supplying material in paste form and a nozzle movable pluridirectionally with respect to the supply means for applying a thread of material to a workpiece. Means are provided for moving the nozzle with respect to the supply means through a nonlinear path. Valve means are controlled by the movement of the nozzle with respect to the supply means for causing material to be fed directly from the supply means to the nozzle during a predetermined portion of the movement of the nozzle with respect to the supply means along the nonlinear path.

Other objects and advantages of the present invention will be more readily understood from the following detailed description of a specific embodiment thereof, when read in conjunction with the appended drawings, in which:

FIG. 1 is a fragmentary, front elevation of a cement applicator, embodying certain principles of the present invention with portions broken away for purposes of clarity;

FIG. 2 is an enlarged, fragmentary, perspective view of the apparatus of FIG. 1;

FIG. 3 is an enlarged, fragmentary, horizontal section 3,652,208 Patented Sept. 4, 1962 ice 2 of the apparatus of FIG. 1, taken along line 33 thereof;

FIG. 4 is an enlarged, fragmentary, vertical section of the apparatus of FIG. 3, taken along line 4-4 thereof, with portions broken away for purposes of clarity, and

FIG. 5 is a vertical section of the apparatus of FIG. 2, taken along line 55 thereof and in a different operating position.

Referring now to the drawings, there is shown apparatus which includes a cement applicator, designated generally by the numeral 15. The applicator 15' is designed to apply parallel worms or threads 16-46 (only one of which is illustrated in FIG. 5 of the drawings) of paste or cement 17 (FIGS. 1 and 2) to a porcelain block, designated generally by the numeral 18 (FIGS. 1, 2 and 5). The worms or threads 16- 16 are applied to the block 18 between side fins 19 19 on the body 21 of the block 18 and immediately adjacent to the longitudinal sides 2222 of a generally rectangular carbon insert 23 positioned loosely in a central rectangular aperture 24 in the porcelain block 18.

The loosely assembled carbon insert 23 and porcelain block 18 are fed from an article-assembling apparatus disclosed in a copending application, Serial Number 34,- 900, filed on June 9, 1960, in the name of V. A. Rayburn, onto a concave conveyor, designated generally by the numeral 27, with the side fins l9-19 of the porcelain block 18 projecting upwardly from the body 21 thereof. The load surface of the conveyor 27 is concaved so that the under surface of the carbon insert 23 will drop below the lower surface of the porcelain block 18 to facilitate a subsequent lapping operation.

A supply of the cement 17 is maintained in a pressurized, cylindrical supply tank, designated generally by the numeral 31. The tank 31 is made of nonmagnetic material, such as nonmagnetic stainless steel, and is secured to a base 30 of the applicator 15. The cement 17 is formed of a water suspension of lead oxide boric anhydride and a suitable suspending agent, such as Cabo-sil which is available from Godfrey L. Cabot, Inc., Boston, Massachusetts. A float-type gauge, designated generally by the numeral 32, is provided to indicate visually the level of the supply of cement 17 in the tank 31. An annular member 33 having an outer concave surface is secured to the hollow ball member of a float 36 of the gauge 32. An O-ring 37 made of elastomeric material is placed in a seat formed by the concave outer surface of the annular member 33 to prevent air from flowing past the float 36.

Communicating with the interior of the cylinder 31, near the top thereof, is an air inlet 38 for maintaining a predetermined pressure of approximately 60 to p.s.i. on the upper surface of the float 36 and, in turn, on the upper surface of the supply of cement 17. A conventional button-head fitting 41 is provided near the bottom of the tank 31, and it is through the buttonhead fitting 41 that additional cement 17 may be forced with a hand pump (not shown) into the tank 31 to replenish the supply of cement 17 as more cement is required.

A rotating magnetic field, similar to a rotating field of a stator of an induction motor, is set up inside of the tank 31 by a plurality of electromagnets 4242 positioned fixedly around the outer periphery of the tank 31. A mixing rotor 43 is positioned in the cement 17 in the tank 31 and is free to rotate and slide therein. The electromagnets 42-42 cooperate'to form a stator for an inductance motor and the mixing rotor 43 constitutes a rotor therefor. The mixing rotor 43 has a plurality of copper bars 44-44 spaced around the outer periphery thereof, which are connected to each other electrically by a pair of copper shorting rings 4545. The mixing rotor 43 also has a plurality of radially inwardly projecting fins 46-46 made of magnetic material, which may be magnetic stainless steel, but is preferably high permeable iron plated with lead zinc or tin to prevent excessive corrosion of the iron in the frit cement 17 in the tank 31.

The fins 46-46 of the mixing rotor 43 are canted so that as the rotor is rotated by the rotating magnetic field, produced by the electromagnets 42-42 in a conventional manner, the fins will tend to force the frit cement 17 contained within the tank 31 downwardly therein. As illustrated in phantom lines in FIG. 1, the mixing rotor 43 is positioned dormantly in the region of rotating magnetic field but below the point of maximum field intensity of the electromagnets 42-42. When the electromagnets 42-42 are energized in a conventional manner by a suitable alternating current, as from a three-phase power supply, the mixing rotor 43 will be attracted upwardly toward the electromagnets 42-42 to a position illustrated in solid lines in FIG. 1. The mixing rotor 43 begins to rotate as the rotor is moved upwardly as a result of the force of the cement 17 on the fins 46-46. Therefore, the starting torque for the mixing rotor 43 will be provided by the movement of the rotor upwardly through the cement 17.

Communicating with the bottom of the tank 31 is a stationary tubular member 49 of a vertical metering valve, designated generally by the numeral 51. The wall of the hollow tubular member 49 is partially covered with an extruded layer of wear and water resistant rubber or plastic material such as Hycar, which is a high abrasion resistant brominated butyl rubber produced by B. F. Goodrich Chemical Co., Cleveland, Ohio, and is provided with a vertically elongated port 52. The tubular member 49 of the valve 51 (FIGS. 2 and 3) is received slidably in a Hycar-lined vertical bore 53 formed in a vertically reciprocable metering block, designated gen erally by the numeral 56. The elastomeric material is used to provide a seal between the moving parts of the valve 51 which will expand as the portions of the valve wear during usage.

The block 56 is secured to a vertically reciprocable pin, designated generally by the numeral 61 (FIG. 4) having rectangular portions 62-62 near the upper and lower ends thereof which slide in a rectangular passage 63 in a guideway 66 secured to the frame 38. A compression spring 67 encompassesthe lower portion of the pin 61, engages the lower extremity 68 of the guideway 66, and is held in place around the pin 61 by a collar 71 secured fixedly thereto by pins 72-72. The lower end of the pin 61 is provided with an axial bore 73 in which a cylindrical pin 74 is mounted slidably. A compression spring 76 is positioned in the bore 73 between the base 77 of the bore 73 and an end 78 of the pin 74. The other end of the pin 74 is secured rigidly to an element 79, which, in turn, is secured to a camming mechanism, designated generally by the numeral 81 (FIG. 1), operated through a shaft 82 in timed relationship with respect to the concave conveyor 27 by appropriate means (not shown).

A straight, horizontally extending, dove-tailed plate 83 with a bifurcated clamp 84 secured fixedly to one end thereof, is mounted in a dove-tailed slot 86 in the block 56 and secured thereto by screws 87-87. A rectangularly shaped, carbon detecting and hold down member 91 is clamped in an adjustable position between the furcations of the clamp 84 by a clamping screW 92. The member 91 extends freely through an aperture 93 in a horizontally extending arm 96 and is used to detect the absence of a carbon insert 23 in the block 18, and to engage the top of the carbon insert 23 to push the insert 23 in place against the conveyor 27 just before application of the worms or threads 16-16 of the cement 17 If a carbon insert 23 is not in the porcelain block 18, the member 91 moves downwardly and permits the block 56 to move downwardly and overtravel to prevent the frit 4E. cement 17 from being removed from the supply tank 31 through the port 52.

The longitudinally extending arm 96 is secured to a vertically reciprocable pin, .designated generally by the numeral 181, having rectangular portions 182-182 near the upper and lower ends thereof which slide in a rectan gular passage 103 in the guideway 66 secured to the frame 30. A compression spring 184 encompasses the lower portion of the pin 101, engages the lower extremity of the guideway 66, and is held in place around the pin 101 by a collar 106 secured fixed thereto by pins 107- 107. The lower end of the pin 161 is provided with an axial bore 188 in which a cylindrical pin 189 is mounted slidably. A compression spring 111 is positioned in the bore 108 between a base 112 of the bore 188 and an end 113 of the pin 109. The other end of the pin 109 is secured rigidly to the element 79.

A pair of depending, resilient members 116-116 are secured adjustably to an outer end of the arm 96. Normally, the resilient members 116-116 are held out of engagement with the porcelain block 18, the port 52 of the tubular member 49 in the valve 51 is held closed, and the hold-down member 91 is held out of engagement with the top of the carbon insert 23 against the action of the compression springs 67 and 184, all by a cam 117, a cam roller 118 and linkage 119 of the camming mechanism 81.

The cam 117 in the mechanism 81, which is operated through the shaft 82 in timed relationship with respect to the concave conveyor 27 by appropriate means (not shown), turns to release the forces exerted thereby on the springs 67 and 104. Accordingly, the resilient members 116-116 are moved downwardly between the fins 19-19 of the porcelain block 18, and into engagement with slanted upper surfaces 121-121 thereof adjacent to the end of the body 21 of the porelain block 18, positioned as shown in FIG. 2 of the drawing, to position the porcelain block 18 and hold the block 18 down firmly against the conveyor 27.

Simultaneously, the valve block 56 and carbon detecting and hold-down member 91 secured thereto are urged downwardly together by the compression spring 67 until the member 91 engages the top of the insert 23 and the port 52 communicates with a Hycar-lined, horizontally extending passageway 126 formed in the metering block 56. However, if there is not a carbon insert 23 in the porcelain block 18, the carbon detecting and hold-down member 91 will allow the spring 67 to push the block 56 down to a level such that a stop member 127 will prevent rthe applicator 15 from applying the worms or threads 16-16 of the cement 17 to the block 18, as explained later.

The passageway 126 communicates with a Hycarlined, horizontally extending cylindrical bore 128 in the block 56, which bore 128 is positioned at right angles with respect to the passageway 126. Mounted slidably in the bore 128 is a closely fitting, Hycar-covered, cylindrical tube 129 provided with a horizon-tally elongated port 131. A rod 132 is secured fixedly to one end of the tube 129 and closes one end thereof. The port 131 of the tube 129 is held normally out of registration with the passageway 126 against the action of a pair of compression springs 133-133 by a cam 134, a cam roller 136 and bell crank 137 of the mechanism 81.

The bell crank 137 is connected to the rod132 by an end of a horizontal plate 138 extending between a pair of collar-s 139-139 secured adjustably to the rod 132 by set screws 141-141. The port 131 in the tube 129 is brought into registry with the passageway 126 in the block 56 during a predetermined length of travel of the tube 129, as the tube 129 is moved horizontally to the right, as viewed in FIGS. 1, 2 and 5, by the compression springs 133-133.

A hollow, substantially V-shaped header member, designated generally by the numeral 146, is mounted at the left-hand end of the tube 129, as Viewed in FIG. 1. The interior of the hollow, V-shaped header member 146 communicates with the interior of the tube 129. Attached to the header member 146, at opposite ends thereof, are a pair of opposed nozzles 147-147, which may be standard hypodermic needles. The discharge ends of the nozzles 147-147 are spaced apart a predetermined distance, equal to the desired spacing between the worms or threads 16-16 of cement 17 which are to be applied to the porcelain blocks 18-18 adjacent to the longitudinal sides 22-22 of the carbon inserts 23-23.

Operation The cement applicator is illustrated in FIG. 1 with the elements thereof in their normal positions immediately before the start of a cement application cycle. It will be assumed that the porcelain block 18, with the carbon insert 23 positioned loosely in the aperture 24 thereof, is brought into the position illustrated in FIG. 1 by the conveyor 27.

The cement application cycle commences with the cam 117 allowing the spring 104 to move the arm 119 downwardly into a position in which the resilient members 116-116 engage the fins 19-19 of the block 18 to align the block 18, and the members 116-116 are urged against the opposite ends of the porcelain block 18 to hold the block firmly against the conveyor 27. Simultaneously, the cam 117 allows the spring 67 (FIG. 4) to move the valve block 56 downwardly and carry therewith the carbon detecting and hold-down member 91, the tube 129, the header member 146 and nozzles 147-147 to a position wherein the member 91 engages the top of the insert 23 to clamp the insert in place on the conveyor 27 and the discharge ends of the nozzles 147-147 are positioned adjacent to the top surface of the porcelain block As the block 56 moves downwardly, the passageway 126 in the block 56 moves into registry with the port 52 in the stationary tubular member 49 of the valve 51, permitting cement 17, under pressure, to enter the passageway 126 from the pressurized supply tank 31. As the cam 117 rotates and tends to move the camming surface thereof out of the way of the roller 118, one or both of the springs 76 and 111 through the associated pins 74 and 109 maintain the roller 118 in engagement with the camming surface of the cam 117.

After the block 56 reaches its lower position, limited by a carbon insert 23 in place in the aperture 24 of the porcelain block 18, the cam 134 releases the bell crank 137 to allow the compression springs 133-133 to move the tube 129 and attached header member 146 and nozzles 147-147 toward the right, as viewed in FIG. 1. However, in the event that a carbon insert 23 is not present in the aperture 24 in the block 18, the block 56 will move downwardly until a hardened steel stop 148 on the end of the rod 132 is below the top of an adjustable, hardened-steel button 149 on the stop member 127 to move the passage 126 past the port 52 to cut 011 the supply of frit cement 17. Also, the stop 127 prevents the tube 129 and attached header member 146 and nozzles 147-147 from being moved to the right by the springs 133-133.

As the discharge ends of the nozzles 147-147 approach the carbon insert 23 during their rightward traverse, the elongated port 131 of the sliding tube 129 moves into registry with the passageway 126 and permits the cement 17, under pressure, to enter the tube 129 and pass through the header member 146 to be discharged from the nozzles 147-147 in the form of the two worms or threads 16-16. As the nozzles 147-147 continue moving to the right with the sliding tube 129, the cement 17 is deposited in the parallel worms or threads 16-16 along opposite sides 22-22 of the carbon insert 23 on the adjacent surface of the porcelain block 18.

When the rightward traverse of the discharge ends of the nozzles 147-147 reach the end of the carbon insert 23, the block 56- is raised vertically to its normal position, as shown in FIG. 1, by the cam 117, and the tube 129 carrying the header member 146 and the nozzles 147-147 is returned to the left to its normal position by the earn 134. Accordingly, the resultant movement of the nozzles 147-147, by the cooperation of the cams 117 and 134, is diagonally upward and to the left, as illustrated in FIG. 5. During this last-described portion of the cycle, the passageway 126 and the ports 52 and 131 are so positioned with respect to each other that there is no flow of cement 17 from the discharge ends of the nozzles 147-147 except for a short, relatively fine, retroflexed portion 151 of the thread 16.

When it is desirable to stir or mix the cement 17, the electromagnets 42-42 are energized to set up a rotating field which draws the mixing rotor 43 from the position illustrated in phantom lines in FIG. 1 to the solid line position so that the rotor 43 rotates and causes the cement 17 to be mixed and forced toward the bottom of the tank 31.

It is to be understood that the above-described arrangements are simply illustrative of the principles of the invention. Other arrangements may be devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. A material dispensing and applicating apparatus, which comprises means for supporting a workpiece, means for supplying cement, a tubular member secured to the cement supply means and having a port in the wall thereof, a metering block for relative movement with respect to the tubular member and having a passageway movable into aligmnent with the port in the wall of the tubular member, a tube mounted for relative movement in a bore in the metering block and having a port movable into alignment with the passageway in the block which extends between the tube and tubular member, nozzle means connected to and movable with the tube for applying cement to the workpiece, means for moving the metering block to place a discharge end of the nozzle means into close proximity to the workpiece, and means for moving the tube axially to move the discharge end of the nozzle means along the workpiece, the movement of the block and the movement of the tube cooperating for causing the port in the tube to communicate with the passageway in the metering block and the passageway in the block to communicate with the port in the tubular member to permit cement to flow from the supply through the tubular member, through the passage in the block, into the tube and out of the nozzle means and be applied in thread form to the workpiece.

2. A cement applicator, which comprises means for supporting a workpiece, means for supplying cement, a vertical tubular member secured to the cement supply means and having a port in the wall thereof, a metering block mounted slidably on the tubular member for vertical reciprocation and having a passageway movable into alignment with the port in the wall of the tubular member, a tube mounted slidably for horizontal movement in a bore in the metering block and having a port movable into alignment with the passageway in the block which extends between the tube and tubular member, nozzle means connected to and movable with the tube for applying cement to the workpiece, means for moving the metering block Vertically to place a discharge end of the nozzle means into close proximity to the workpiece, and means for moving the tube axially horizontally to move the discharge end of the nozzle means along the workpiece, the vertical movement of the block and the horizontal movement of the tube cooperating for causing the port in the tube to communicate with the passageway in the metering block and the passageway in the block to communicate with the port in the tubular member to permit cement to flow from the supply through I! the tubular member, through the passage in the block, into the tube and out of the nozzle means and be applied in thread form to the workpiece.

3. A cement applicator, which comprises means for supporting a workpiece, means for supplying cement, a vertical tubular member secured to the cement supply means and having a port in the wall thereof, a camming mechanism, resilient means, a metering block mounted slidably on the tubular member for vertical reciprocation and having a passageway held normally out of alignment with the port by the camming mechanism but movable into alignment with the port in the wall of the tubular member by the resilient means, a tube mounted slidably for horizontal movement in a bore in the metering block and having a port held normally out of alignment with the passageway in the block by the camming mechanism but movable into alignment with the passageway in the block which extends between the tube and tubular memher by the resilient means, nozzle means connected to and movable with the tube for applying cement to the workpiece, the resilient means operating to move the metering block vertically downwardly to place a discharge end of the nozzle means into close proximity to the workpiece and to move the tube axially horizontally to move the discharge end of the attached nozzle means along the workpiece, the vertical movement of the block and the horizontal movement of the tube cooperating for causing the port in the tube to communicate with the passageway in the metering block and the passageway in the metering block to communicate with the port in the tubular member to permit cement to flow from the supply through the tubular member, through the passage in the block, into the tube and out of the nozzle means and be applied in thread form to the workpiece.

4. A cement applicator, which comprises means for supporting a workpiece, means for supplying cement, a vertical tubular member coated with elastomeric material secured to the cement supply means and having a port in the wall thereof, a camming mechanism, resilient means, a metering block mounted slidably on the tubular member extending into a first bore in the block lined with elastomeric material for vertical reciprocation and having a passageway lined with elastomeric material held normally out of alignment with the port by the camming mechanism but movable into alignment with the port in the wall of the tubular member by the resilient means, a tube coated with elastomeric material mounted slidably for horizontal movement in a second bore in the metering block lined with elastomeric material and having a port held normally out of alignment with the passageway in the block by the carnming mechanism but movable into alignment with the passageway in the block which extends between the tube and tubular member by the resilient means, nozzle means connected to and movable with the tube for applying cement to the workpiece, the resilient means operating to move the metering block vertically downwardly to place a discharge end of the nozzle means into close proximity to the workpiece and to move the tube axially horizontally to move the discharge end of the attached nozzle means along the workpiece, the vertical movement of the block and the horizontal movement of the tube cooperating for causing the port in the tube to communicate with the passageway in the metering block and the passageway in the metering block to communicate with the port in the tubular member to permit cement to flow from the supply through the tubular member, through the passage in the block, into the tube and out of the nozzle means and be applied in thread form to the workpiece.

5. A cement applicator, which comprises a pair of opposed movable nozzles for applying a pair of threads of cement on a block immediately adjacent to sides of an insert positioned in an aperture in the block, means for supporting a loosely assembled insert and block under the nozzles, a tank for supplying cement to the nozzles, a valve having a vertical tubular member secured to the tank and having a vertically extending port in the wall thereof and a metering element mounted slidably on the tubular member for vertical reciprocation and having a passageway movable into alignment with the port in the wall of the tubular member, a tube mounted slidably for horizontal movement in a bore in the metering element and having an elongated port movable into alignment with the passageway in the metering element which extends between the tube and tubular member, means for moving discharge ends of the nozzl s into close proximity to the block, and means for moving the discharge ends of the nozzles along the length of the insert and simultaneously causin the port in the tube to communicate with and move along the passageway in the metering element to permit cement to flow into the tube and out of the nozzles and be applied in threads to the block immediately adjacent to the sides of the insert.

6. A cement applicator, which comprises a pair of opposed movable nozzles for applying a pair of threads of cement on a block immediately adjacent to sides of an insert positioned in an aperture in the block, means for supporting a loosely assemble-d insert and block under the nozzles, a tank for supplying cement to the nozzles, a valve having a vertical tubular member secured to the tank and having a vertically extending port in the wall thereof and a metering element mounted slidably on the tubular member for vertical reciprocation and having a passageway movable into alignment with the port in the wall of the tubular member, a tube mounted slidably for horizontal movement in -a bore in the metering element and having an elongated port movable into alignment with the passageway in the metering element which extends between the tube and tubular member, means for moving discharge ends of the nozzles into close proximity to the block, means for aligning the loosely assembled insert and block under the nozzles and for clamping the block in place on the support means, and means for moving the discharge ends of the nozzles along the length of the insert and simultaneously causing the port in the tube to communicate with and move along the passageway in the metering element to permit cement to flow into the tube and out of the nozzles and be applied in threads to the block immediately adjacent to the sides of the insert.

7. A cement applicator, which comprises a pair of 0P- posed movable nozzles for applying a pair of threads of cement on a block immediately adjacent to sides of an insert positioned in an aperture in the block, means for feeding a loosely assembled insert and block under the nozzles, a tank for supplying cement to the nozzles, a valve having a vertical tubular member secured to the tank and having a vertically extending port in the wall thereof and a metering element mounted slidably on the tubular member for vertical reciprocation and having a passageway movable into alignment with the port in the wall of the tubular member, a tube mounted slidably for horizontal movement in -a bore in the metering element and having an elongated port movable into alignment with the passageway in the metering element which extends between the tube and tubular member, means for moving discharge ends of the nozzles into close proximity to the block, means for clamping the insert in place in the block against the feeding means and for detecting the absence of an insert in the block to prevent discharge of cement from the nozzles unless both the insert and the block is present on the feeding means under the nozzles, and means for moving the discharge ends of the nozzles along the length of the insert and simultaneously causing the port in the tube to communicate with and move along the passageway in the metering element to permit cement to flow into the tube and out of the nozzles and be applied in threads to the block immediately adjacent to the sides of the insert.

8. A cement applicator, which comprises a pair of opposed movable nozzles for applying a pair of threads of cement on a porcelain block immediately adjacent to sides of a carbon insert positioned in an aperture in the porcelain block, a concavely shaped conveyor for feeding a loosely assembled carbon insert and porcelain block under the nozzles, a tank for supplying cement to the nozzles, a valve having a vertical tubular member secured to the tank and having a vertically extending port in (the wall thereof, a metering block mounted slida bly on the tubular member for vertical reciprocation and having a passageway movable into alignment with the port in the wall f the tubular member, a tube mounted slidably for horizontal movement in a bore in the metering block and having an elongated port movable into alignment with the passageway in the metering block which extends between the tube and tubular member, means for moving discharge ends of the nozzles into close proximity to the porcelain block, means for aligning the loosely assembled carbon insert and porcelain block under the nozzles and for clamping the porcelain block in place on the concave conveyor, means for clamping the carbon insert in place in the porcelain block against the conveyor and for detecting the absence of a carbon insert in the porcelain block to prevent discharge of cement from the nozzles unless both the carbon insert and the porcelain block is present on the conveyor under the nozzles, and means for moving the discharge ends of the nozzles along the length of the carbon insert and simultaneously causing the port in the tube to communicate with and move along the passageway in the metering block to permit cement to flow into the tube and out of the nozzles and be applied in threads to the porcelain block immediately adjacent to the sides of the carbon insert.

9. A cement applicator, which comprises a pair of opposed movable nozzles for applying a pair of threads of cement on a porcelain block immediately adjacent to sides of a carbon insert positioned in an aperture in the porcelain block, a concavely shaped conveyor for feeding a loosely assembled carbon insert and porcelain block under the nozzles, a frame, a supply tank for the cement secured to the frame, a float-type gauge for the supply tank having a float supported by the cement which fits closely and slidably in the tank, an annular member having an outer concave surface secured to the float of the gauge, an ring made of elastomeric material in a seat formed by the concaved surface of the annular member to prevent fluid from flowing between the float and the inside surfaces of the tank, means for maintaining a predetermined amount of fluid pressure on the upper surface of the float and in turn on the upper surface of the cement, a plurality of electromagnets positioned adjacent to the tank in spaced relationship around the outer periphery of the tank, means for energizing the electromagnets sequentially to produce a rotating magnetic field in the tank, a mixing wheel in the tank being free to rotate and reciprocate in the cement therein, having canted radially inwardly projecting fins made of magnetic material and being positioned normally in the field but below the points of maximum field intensity of the electroinagnets so that the wheel will start to rotate when the Wheel is moved from the normal position thereof into the points of maximum field intensity, a vertical tubular member secured to the tank and having a vertically extending port in the wall thereof, a metering block mounted slidably on the tubular member for vertical reciprocation and having a passageway movable into alignment with the port in the Wall of the tubular member, a tube mounted slidably for hori zontal movement in a bore in the metering block and having an enlongated port movable into alignment with the passageway in the metering block which extends between the tube and tubular member, resilient means for moving the metering block vertically downwardly and for moving the discharge ends of the attached nozzles downwardly into close proximity to the porcelain block, resilient means for aligning the loosely assembled carbon insert and porcelain block under the nozzles and for clamping the porcelain block in place on the concave conveyor, means secured to the metering block and movable therewith for clamping the carbon insert in place in the porcelain block against the conveyor and for detecting the absence of a carbon insert in the porcelain block to prevent discharge of cement from the nozzles unless both the carbon insert and the porcelain block is present on the conveyor under the nozzles, cam means for holding the port in the tubes, the passageway in the metering block and the port in the tubular member normally out of alignment with each other, and resilient means for moving the tube and the discharge ends of the attached nozzles horizontally along the length of the carbon insert, the vertical movement of the metering block and the horizontal movement of the tube cooperating for causing the port in the tube to communicate with the passageway in the metering block and the passageway in the metering block to communicate with the port in the tubular member to permit cement to flow from the supply tank through the tubular member, through the passage in the metering block, into the tube and out of the nozzles and be applied in thread form to the workpiece.

References Cited in the file of this patent UNITED STATES PATENTS 2,383,023 Sykes et a1. Aug. 21, 1945 2,587,284 Brewer et al. Feb. 26, 1952 2,798,456 Pearson July 9, 1957 2,951,261 Sherman Sept. 6, 1960 

